Some time ago I bought an Olympus m.zuiko digital 75-300mm to take bird photos and I never got an acceptable photo with this lens. Recently I bought a TC1.4 to use with my old zuiko 50-200mm and the results were quite different. Last week I did a comparison, that I post on this site, between the two lens. I got some answers but none of them to explain what the problem was. During this week I have read some explanations about the shutter problem vibration with some lens.

Today I decide investigate a little more about this issue and I want to share results with you.

What I realized it was that for speed below 1/160, photos become blurred. This effect can be attenuated activating the Anti-shock to 1/8 but without eliminate completely the issue.

You think that this issue normal to this lens? For me it becomes useless. Only at very good light and at high aperture of 6.7 I can get speed above 1/160.